Komatsu Galeo PC138US-8 User Manual

SEN02469-01 40 Troubleshooting
14 PC138US, USLC-8
S-5 Engine does not rotate smoothly 1
*1: Displayed failure code [CA689]
*2: Displayed failure code [CA778]
General causes why engine does not rotate smoothly
q Air in fuel system
q Defective speed sensor (Error at degree that it is not indicated)
Causes
Insufficient fuel in tank Clogged air breather hole of fuel tank cap Leaking or clogged fuel piping, entry of air Clogging of fuel filter Clogged injector, defective spray (dirt in injector) Defective Ne speed sensor, wiring harness Defective Bkup speed sensor, wiring harness
Questions
Confirm recent repair history
Degree of use of machine Operated for long period
E
Hunting
Occurs at a certain speed range
QQ
Occurs at low idle QQQQQ
Occurs even when speed is raised QQQ
Occurs on slopes w
Replacement of filters has not been carried out according to Operation and Maintenance Manual w
When fuel tank is inspected, it is found to be empty w
Check items
Air breather hole of fuel tank cap is clogged w
Rust and water are found when fuel tank is drained Q
Fuel is leaking from fuel piping w
When priming pump is operated, it makes no reaction or it is heavy wQ
Troubleshooting
When air is bled from fuel system, air comes out q
Inspect fuel filter directly q
When a cylinder is cut out for reduced cylinder mode operation, engine speed does not change q
Carry out troubleshooting according to “Abnormality in Ne speed sensor (*1)” indicated by code q
Carry out troubleshooting according to “Abnormality in Bkup speed sensor (*2)” indicated by code q
Remedy
Add
Clean
Replace Replace Replace Replace Replace

Komatsu Galeo PC138US-8 Specifications

General

Brand	Komatsu
Model	Galeo PC138US-8
Category	Excavators
Language	English